81428441 has 6 divisors (see below), whose sum is σ = 85123290. Its totient is φ = 77887568.

The previous prime is 81428407. The next prime is 81428467. The reversal of 81428441 is 14482418.

It can be written as a sum of positive squares in only one way, i.e., 54169600 + 27258841 = 7360^2 + 5221^2 .

It is not a de Polignac number, because 81428441 - 2⁶ = 81428377 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81428398 and 81428407.

It is not an unprimeable number, because it can be changed into a prime (81422441) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 76436 + ... + 77493.

It is an arithmetic number, because the mean of its divisors is an integer number (14187215).

Almost surely, 2^81428441 is an apocalyptic number.

It is an amenable number.

81428441 is a deficient number, since it is larger than the sum of its proper divisors (3694849).

81428441 is a wasteful number, since it uses less digits than its factorization.

81428441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153975 (or 153952 counting only the distinct ones).

The product of its digits is 8192, while the sum is 32.

The square root of 81428441 is about 9023.7708858326. The cubic root of 81428441 is about 433.4363927787.

The spelling of 81428441 in words is "eighty-one million, four hundred twenty-eight thousand, four hundred forty-one".